OK, you might not be paranoid – perhaps that priority mail box IS spying on you

[Thomas Renck] recently picked up a 1000mW wireless video transmitter that he ultimately planned to mount in an RC plane. Before he strapped it on a plane to potentially kiss it goodbye for good, he wanted to play with it a while to see what it was capable of.

After a friend helped him determine the camera’s maximum range (about 1900 feet on open ground), he thought it would be fun to strap it on his nitro R/C truck. That didn’t work out so well due to some vibration issues, so he constructed a makeshift R/C car from the shipping box the camera arrived in, along with some other odds and ends.

As you can see in the video below, the propeller-driven “Boxmobile” zips along quite nicely. The video feed from the camera is pretty impressive too, allowing him to easily guide the car while it’s well out of sight.

At nearly $350, the self-proclaimed “ghetto-bot” is certainly not cheap, though we hear body repairs are a piece of cake!

@eric It sounds like you just took your first introductory science class (I don’t intend that to be condescending it’s just that precision vs accuracy and significant digits are usually introductory concepts drilled hard in an intro-level course)

Let me say two things. First, 1000 mW and 1 W actually have the same number of significant digits. The trailing zeros in 1000 are not significant; if they were you would typically note that with either a bar at the last significant digit or if all zeros were significant you would put a decimal at the end.

Second, I wouldn’t put much stock into using significant digits as a means of error analysis, it’s a hackneyed and flawed technique used to “dumb down” actual error analysis that usually isn’t worth the effort taken to learn it; kinda like cursive or roman numerals.

It’s more likely that the bulk of video transmitters fall in the 1-1000 mW range and it’s just common to represent transmitting power for small devices in mW; in the same way you wouldn’t say you were .002 km tall or that NY to LA is .0000000000004 lightyears.

I’ve done this before with an amateur-band camera and a futaba aircraft-band (72 mhz) rx, and the camera’s output swamped the frontend on the rx so badly we had to put a lowpass filter on the rx antenna lead and mount the rx in a metsl box for shielding. It still cut back on the max range of the receiver… probably leaking in through the servo leads.

Good Point. We’ve resorted to multiple layers of RF Mitigation for such cases. Depending on if it’s a ‘Raw Desense” or Harmonics/Intermod- or other paths. There’s a set of basic initial design rules that pays off in Less Hassles. A spoonful of Ferrites,Chokes,Bypass Caps etc can banish many could have been demons before they hatch.

I taught it as “Think Like a Gremlin” to thought experiment where RFI/EMI could stuff a build totally.

I like the idea, and I have enough junk at home to do the same. However, the pusher prop just isn’t safe. I would either gear-drive the wheels or put the prop in an enclosure, kind of like a house fan. I have a huge scar on my hand from a 5″ prop ripping through me at 20k RPM…